© Clinical Science Applied to Nursing /SONMS/Cardiff University/092005 Skin Introduction.

© Clinical Science Applied to Nursing /SO© Clinical Science Applied to Nursing /SONMS/Cardiff University/092005NMS/Cardiff University/092005

SkinSkin

IntroductionIntroduction


Learning OutcomesLearning Outcomes List the layers of the skinList the layers of the skin List the functions of the skinList the functions of the skin Briefly describe the layers of the epidermisBriefly describe the layers of the epidermis Outline the functions of: Outline the functions of:

Keratinocytes Keratinocytes MelanocytesMelanocytes Langerhan cellsLangerhan cells Merkel cellsMerkel cells

Briefly describe the DermisBriefly describe the Dermis Distinguish between the papillary & reticular layers of Distinguish between the papillary & reticular layers of

the dermisthe dermis Briefly explain the structure & function of hair, nails & Briefly explain the structure & function of hair, nails &

glandsglands


OVERVIEW of SKINOVERVIEW of SKIN

EpidermisEpidermis

DermisDermis

Subcutaneous LayerSubcutaneous Layer

((network of fat and network of fat and collagen cells, functions as collagen cells, functions as an insulator)an insulator)


General Functions of the skinGeneral Functions of the skin

Protective barrier against pathogensProtective barrier against pathogens Helps regulate temperatureHelps regulate temperature Gathers sensory information from the Gathers sensory information from the

environmentenvironment Synthesis of Vitamin DSynthesis of Vitamin D Aesthetics and communicationAesthetics and communication Excretion (minor function)Excretion (minor function)


THE EPIDERMISTHE EPIDERMISThe epidermis is The epidermis is composed ofcomposed of LayersLayers

(or Strata)(or Strata)(see left side labels of (see left side labels of

diagram)diagram)

Epidermal cells Epidermal cells include:include:

KeratinocytesKeratinocytes

MelanocytesMelanocytes

Langerhans cellsLangerhans cells

Merkel cellsMerkel cells


Cells in the EpidermisCells in the Epidermis

In the epidermis, cells:In the epidermis, cells:

* are very interactive* are very interactive

* produce protein* produce protein

* differentiate (* differentiate (change as they progress to change as they progress to

the surfacethe surface))

* start to die towards the surface* start to die towards the surface

* are worn away at the surface* are worn away at the surface[SCRATCH YOUR SKIN WITH YOUR NAILS AND YOU WILL TAKE [SCRATCH YOUR SKIN WITH YOUR NAILS AND YOU WILL TAKE

AWAYS THOUSANDS OF TOP CELLS THAT HAVE TO BE AWAYS THOUSANDS OF TOP CELLS THAT HAVE TO BE REPLACED]REPLACED]


Stratum BasaleStratum Basale

* Innermost layer* Innermost layer

* A single layer of basal cells * A single layer of basal cells

• Cells continually divideCells continually divide • (by Mitosis)(by Mitosis) to form theto form the • Epidermal cellsEpidermal cells


Stratum Spinosum (‘spiny’ layer)Stratum Spinosum (‘spiny’ layer) Also known as the Also known as the

squamous cell layersquamous cell layer Thickest layer of the Thickest layer of the

epidermisepidermis This layer contains:This layer contains:

• Keratinocytes – produce Keratinocytes – produce keratinkeratin

• Langerhan's cells - Langerhan's cells - involved in immunityinvolved in immunity

• Melanocytes – produce Melanocytes – produce melaninmelanin


Stratum GranulosumStratum Granulosum//Stratum LucidumStratum Lucidum Cells have changed Cells have changed

form & functionform & function

Some lose cytoplasm / Some lose cytoplasm /

DNA (others continue DNA (others continue to synthesis keratin)to synthesis keratin)

Cells get flatter and Cells get flatter and adhere togetheradhere together

The dying process The dying process startsstarts


The stratum corneum The stratum corneum

Outermost layer of epidermisOutermost layer of epidermis

Dead keratinized multi-layered Dead keratinized multi-layered stratastrata

[More wear and tear [More wear and tear More More layerslayers]]

Dead cells are continuously shedDead cells are continuously shed

Shedding process slows with ageShedding process slows with age

Complete cell turnover: Complete cell turnover:

28 – 30 days in young adults28 – 30 days in young adults

45 – 50 days in elderly adults45 – 50 days in elderly adults


KeratinocytesKeratinocytes Building blocksBuilding blocks of the Epidermis. of the Epidermis.

• Joined to the basement membrane & cell Joined to the basement membrane & cell to cell by Hemidesmosomes (an anchoring to cell by Hemidesmosomes (an anchoring complex)complex)

• ProduceProduce KERATIN KERATIN ( (fibrous protein that fibrous protein that water proofs the skin)water proofs the skin)

Involved in Involved in ImmunityImmunity


KERATINKERATIN

SoftSoft KERATIN-KERATIN-found in found in skin. skin.

HardHard KERATIN KERATIN found nails.found nails.

Function: Function: protectionprotection


MelanocytesMelanocytes Synthesize Synthesize pigment granulespigment granules

Pigment Granules = MELANOSOMES -Pigment Granules = MELANOSOMES - these contain these contain melanin, melanin, (brown pigment for (brown pigment for UV protection). UV protection).

Melanosomes are transferred to Melanosomes are transferred to KeratinocytesKeratinocytes through dendritic processes through dendritic processes


MELANIN & Skin ColourMELANIN & Skin Colour

Melanocytes - scattered throughout Melanocytes - scattered throughout the base layer of the epidermis the base layer of the epidermis

The amount of melanin produced by The amount of melanin produced by the cells determines skin colourthe cells determines skin colour

Amount of Melanin affected by: Amount of Melanin affected by:

Genes, Sunlight, Genes, Sunlight,

HormonesHormones

© Clinical Science Applied to Nursing /SONMS/Cardiff University/092005

Colour Transfer


Infection Control & the SkinInfection Control & the Skin

Infection control involves:Infection control involves:

Langerhans cells (attach themselves to Langerhans cells (attach themselves to antigens that invade damaged skin and alert antigens that invade damaged skin and alert the immune system to their presence)the immune system to their presence)(Langerhans cells originate from the Bone (Langerhans cells originate from the Bone Marrow)Marrow)

LymphocytesLymphocytes

Interleukin 1 Interleukin 1 Interleukin 2 Interleukin 2


Merkel CellsMerkel Cells Tactile cells Tactile cells

found all touch found all touch areasareas

Their function is Their function is to detect to detect touchtouch


The DermisThe Dermis

Located under the epidermisLocated under the epidermis Thickest layer of the skinThickest layer of the skin Contains blood vessels, lymph Contains blood vessels, lymph

vessels, hair follicles, sweat glands, vessels, hair follicles, sweat glands, sebaceous glands, nerve endings, sebaceous glands, nerve endings, collagen and elastincollagen and elastin

Made up of two sublayers:Made up of two sublayers:• Papillary layer (upper)Papillary layer (upper)• Reticular layer (lower)Reticular layer (lower)


PAPILLARY LAYERPAPILLARY LAYER

Capillary blood flow

Nerve Fibres

papilla

Capillary Dilation to increase blood flow

Defence against!


THE RETICULAR LAYER

•Tough and durable

•Random collagen fibres - gives rise to the gives rise to the cleavage lines on the body and finger printscleavage lines on the body and finger prints.

Contains:

blood & lymph vessels

nerve endings, fat, oils glands & hair roots


Special Glands in the epidermisSpecial Glands in the epidermis

SWEAT GLANDSSWEAT GLANDS • watery secretions – evaporates to cool the watery secretions – evaporates to cool the

bodybody

SEBACEOUS GLANDSSEBACEOUS GLANDS • oily oily sebumsebum – protective: lubricates & – protective: lubricates &

prevents water lossprevents water loss• also thought to have an antibacterial also thought to have an antibacterial

functionfunction


Glands • ECCRINE- Sweat

Transports sweat to regulate body temperature

• APOCRINE- SebaceousOpens from the hair follicle Secretes oily substance

(mixes with bacteria on skin surface -) How do you notice this?


Skin StructuresSkin Structures HAIRHAIR

• requires a hair follicle & muscle to moverequires a hair follicle & muscle to move

NAILSNAILS• a Hardened keratinized plate a Hardened keratinized plate

Sebaceous glandsSebaceous glands • lubricate the hairlubricate the hair

Apocrine glandsApocrine glands (axilla/groin) (axilla/groin) • give off an odourgive off an odour

© Clinical Science Applied to Nursing /SONMS/Cardiff University/092005 Skin Introduction.

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Transcript of © Clinical Science Applied to Nursing /SONMS/Cardiff University/092005 Skin Introduction.